To apply clinical, immunologic, histochemical, pharmacologic, electrophysiologic, autoradiographic, radionuclide-scanning, tissue-culture and electron microscopic techniques to investigate the etiology and pathogenesis of myasthenia gravis. To seek new or improved methods of treatment. BIBLIOGRAPHIC REFERENCES: Cook, J. D., Trotter, J. L., Engel, W. K. and McIntosh, C. L.: Altered immunologic cell populations in thymuses from myasthenia gravis patients (MGP). Neurology, 27: 365, 1977. Engel, W. K., Trotter, J. L., and McFarlin, D. and McIntosh, C. L.: Thymic epithelial cell contains acetylcholine receptor. Lancet, 1: 1310-1311, 1977.